Method and apparatus for making grooved caps



w fl A i 3 Sheets-Sheet 1 5. ZESBAUGH N Inventor-r Lam na/42 225510; B3 7%. Attorney.

METHOD AND APPARATUS FOR MAKING GROOVED CAPS June 1, 1948.

Filed April 21, 1945 June 1, 1948. ZESBAUGH 2,442,527

METHOD AND APPARATUS FOR MAKING GROOVED CAPS I Filed April 21, 1943 3 Sheets-Sheet 3 Inventor- Q n Law/751m: Zss /u/w Patented June 1, 1948 METHOD AND APPARATUS FOR MAKING GROOVED CAPS Lawrence G. Zesbaugh, Minneapolis, Minn., as-

signor to John G. ONeil, Faribault, Minn.

Application April 21, 1943, Serial No. 483,921

11 Claims. 1

This invention relates to a method and apparatus for forming a ring or cap, and particularly for forming a grooved ring or cap. Caps with grooves or threads formed therein on the inner cylindrical wall thereof are now commonly used as tops or closures for many kinds of containers.

It is an object of this invention to provide a simple and eflicient method and apparatus for forming a grooved or threaded cap of material adapted to be pressed into shape, said cap being so formed that it can readily be removed from the apparatus.

It is a further object of this invention to provide a method whereby a groove and rib can be formed on the inner wall of a cap, said groove or rib and groove being formed in successive steps, part of the same being formed in one step and part in another step.

It is still another object of the invention to provide a method for forming a groove or groove and rib on the inner wall of a cap which con-' sists of forming circumferentially spaced portions of said groove in one operation and subsequently forming the alternate portions of said groove in another operation.

It is also an object of this invention to provide a method and apparatus for forming a grooved cap or ring comprising an inner die having a projecting rib formed thereon, an outer die adapted to move over a cap placed on said inner die and having portions closely fitting said cap so that said cap is pressed against said inner die at said portions, said outer die also having'portions of larger dimension which do not engage said cap tightly and into which portions of said cap may extend, a second outer die having circumferentially spaced portions adapted to closely fit said cap to press portions thereof against said inner die and also having circumferentially spaced portions of larger dimension, said dies being 50 arranged that the said larger portions of said outer dies are alternately arranged whereby said cap will be grooved for substantially its whole extent but will not be made to firmly adhere to said inner die.

It is further an object of the invention to provide an apparatus for forming a cap comprising an inner die having a projecting rib on its periphery, an outer die adapted to move over a cap placed over said inner die to compress said cap longitudinally and form a groove therein by means of said inner die, said outer die also having a portion engaging the top of said cap and adapted to form a circumferential groove therein.

, It is also an object of the invention to provide an apparatus for forming a grooved cap comprising an inner die having means thereon to form a groove in said cap, said inner die having a rigid portion for supporting the edge of said cap, an outer die movable over a cap disposed on said inner die and adapted to compress said cap, said outer die being yieldingly mounted.

It is further an object of the invention to pro-- vide such an appartus as set forth in the preceding paragraph, said outer die having a portion for engaging to top of said cap which is unyielding and said inner die having a portion engaging the inside of said top portion of the cap which is yieldingly mounted.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accom- I panying drawings in which like reference characters refer to similar parts throughout the several views and in which:

Fig. 1 is a view partly in side elevation and partly in central vertical section of the dies and plungers used in forming the cap;

Fig. 2 is a central vertical section of one of the sets of dies in cap forming position;

Fig. 8 is a partial vertical section on an enlarged scale of the cap forming portion ofthe dies;

Fig. 4 is a horizontal section taken on line l4 of Fig. 2 as indicated by the arrows;

Fig. 5 is a horizontal section taken on line 5-5 of Fig. 1 as indicated by the arrows;

Fig. 6 is a horizontal section similar to Fig. 5 taken through the cap rim;

Fig. '7 is a somewhat diagrammatic plan view of the die-carrying turret and cooperating plunger, a portion being shown in horizontal section;

Fig. 8 is a partial vertical section through the finished cap; and

Fig. 9 is a central vertical section through the cap before being placed in the dies.

Referring to the drawings, a machine is shown which comprises lower die assemblies i5 and upper die assemblies l6, l1 and I8. While these may be variously arranged, one desirable arrangement is that illustrated in Fig. 7 where" the lower dies l5 will be carried on a revoluble turret 19. While this turret could revolve in either direction, in the embodiment of the invention illustrated it is rotated in the direction indicated by the arrow in Fig. '7. The method and apparatus of the invention are directed to forming grooves or threads on a ring or cap and while various forms of blanks might be used in the embodiment of the invention illustrated a blank or partly finished cap 20 shown in Fig. 9 is used. This cap comprises a ring No of some compressible dense material such as cardboard, fiber, etc. A cup-like portion 2% extends along the inner wall of ring 20 and across the top thereof and this can be made of lighter sheet material of fiber, paper, etc. Preferably a sealing disk 200 is used which is placed underneath the top 20b and is somewhat softer sheet material such as paper or fiber and is adapted to engage the top of the container. also be formed of various metals.

The lower dies I are of similar construct on and comprise an outer cylindrical portion a having a flange secured to a base or the turret I9 by circumferentially spaced screws 22. member I5b fits inside of member I5a, being ver tically slidable relatively thereto, the same having a lower outwardly extending flange I5c adapted to engage a shoulder adjacent the bottom of member I5a to limit its upward movement. Member I 5b at its top portion is of reduced diameter and has secured thereto in any suitable manner as by the threads-shown, .a ring I'5d of hard metal. This ring as shown, .has formed on its periphery, ribs I5e. While ribs I5e could be variously formed, in the embodiment of the invention illustrated they are arranged as helices or threads. Member I51) has a top disk-like portion with a central aperture I5f and a member 23 having a tapered or frustoconical top portion extends slightly into opening I5f. A screw 24 is threaded into the plug or member 23 and'hasa head disposed below the same. Plug 23 has a depending portion 23a of reduced diameter loosely fitting into the top of a compression coiled spring 25 which rests on the base or turret I9. Plug 23 has another portion 23?) extending downwardly into spring 25 and the head of bolt'24 extends I'll The grooved cap couldalso has an inner member I8c similar to members I60 and Ho. Compression coiled springs 29 hold member I 8a downwardly and its downward movement is limited by the flange IBd engaging a shoulder on member I80. Members I10 and I80 have the ridges I'Ie and I8e respectively, similar to the ribs or ridges Ifie and also have the outer ribs I1 and I8 similar to the ridges I61. Member Ila. difiers from member I6a however, in that its opening I'Ib instead of being perfectly cylindrical has enlarged portions Hg and while the number of these portions might vary, in the embfldimcnt of the invention illustrated they are shown as four in number and equally spaced about member Ila. Member I8a also has enlarged portions I89 about its opening I8b which downwardly into spring 25. Member I5a has a hollow groove or channel I So at its inner edge adjacent member I5'b.

Cooperating with the dies I5 are the upper dies I6, I1 and I8 and in the embodiment of the invention illustrated-these are shown as carried in a plunger head 21 carried on'a'plunger 28 which will be reclprocated by some suitable operating mechanism. Die assembly I 6 comprises a member IBa of general cylindrical form having an opening I5!) which is of a diameter sufilcient to move over and surround the blank 2!) carried on the lower die assembly I5. Member I6 is slidable on an inner member I 60 which is seated rigidly in member 21 and secured therein by the headed screw 28. Compression coiled springs 29 have one end seated in recesses in member 21 and their other ends seated in recesses in member Ifia. Member I60. has an inwardly extending flange I6d engaging the shoulder on member lfic 'sald flange limiting the downward movement of member IBa. Member I60 is' provided adjacent its edge with a V-shaped rib I Be and also has a sharp ridg I6 at its edge which extends'downwardly. The die assembly I1 is similar in construction to die member I6 in having member IIa and mem= ber IIc as Well as the compression coiled springs 29. Member We is also held in place by one of the screws 28. Member I lahas an opening there.- in which is also of suflieient size to move over the cap '20 disposed on the lower die and member IIafhas a flange IId engaging the shoulder on member He to limit the downward movement of member IIa. Member I8 has a portion I8a simn-v lar to members Ifia and I m and said die assembly are similar to the portions I Ig and these are equally and clrcumferentially spaced and shown as four in number. The die assemblies I1 and IB will be so disposed in member 21 that the portions I8g will alternate with the openings IIg relative to the lower die or in other words, the portions IBg will be disposed between the portions Hg in relative location. The lower portion of the openings I6b, 11b, and I8!) are slightly outwardly beveled at their lower edge as shown at IBh in Fig; 1.- This bevel of course Will be present in members Ila. and 18a between the enlargements Hg and I8g. Ribs 11 and I.8f are omitted at the enlarged portions Hg and I-89 as shown in Fig; 5.

In performing the method of the invention; in the embodiment of the apparatus illustrated, theblanks or caps '29 which have been previ u y turret IQ. rotated distances equal to the circumferential distance between the die assemblies I5. The cap- Dlaced .on the lower die I5 will first come under the member IIia or the die assembly I6. As the plunger2'8 descends member 16a will surround, the cap 20 and will move downward until itslower surface engages the top surface of member I511. Its movement will thusbe arrested and further downward movement of member 21 will" compr ss he springs 29.. Member [60 moves downwardl and the cap :20 is compressed andrit:

will be moved somewhat lightly aga nst the ribs I512. The pre ure of the cap a ainst ribs Hie will not however. be snflicient to form completed grooves in the inner wall of the cap. The ribs IIie form a groove in the top of the cap just.

inwardly of ring 20 as shown in Fig. l and the rib I63 will form a slight bevel at the outer corner of the cap as shown in Figs. 1 and 8. The plunger.

21 will now be raised and the turret will be rotated another step, bringing the ca on the lower ,die assembly Iii-beneath die assembly I'I. Asthe die assembly I? descends member fla will surround the cap and member I5b will be depressed asbe; fore against spring 25 so that the lower edge-of. the ring part of the cap will seat in the groove- I5g. The member IIa will surround the cap and at the portions between portion I'lg the side of the cap will be forced very strongly against the member I5d and its ribs I5e. The grooves and ribs formed in the cap will thus be completely formed at these portions between portions I Ig.. The cap can expand slightly into the enlarged port-ions Hg and the cap will notice caused to adhere very tightly to the member I'Sd. Plunger 27' is again raised and the can now rotates with. the turret and is brought beneath the dietassem-l bly I8. As this descends with member 21. the cap is again compressed between members ltaand Mid and the portions thereof which occupied the enlarged portions l-lg now are. disposed between theportions: lBo and theseportions have the wall of the: cap. forced very and strongly against member [5d and the ribs lie. so that. the grooves and ribs formed on the cap are now formed completely about the same. It will thus be seen'that part of the cap is finished by die assembly I! as to the, grooves and: ribs and the remainder is finished by the die assembly I8. The openings Ill: and. i811 may be slightly smaller than the opening. I612. When the portions; of. members lBa between enlarged portionsl-Sg engage the cap and force it against the ribs tie.- other p rtions of the cap-can expand slightly into the openings Ida" and will thus not be tightly engaged. As. a result, the cap will not be caused to adhere tig tly to the; member I 5d. It has been found in practice that if the threads are formed completely around the cap inone operation, the cap adheres so tightly to the diev that difficulty is experienced in removing it. With the present, method and apparatus. the threads are formedin several operations and the cap is not tightly fastened to the dieand can be easily removed. The slight bevel I611. enables the die to move easily over the cap 20 on the lower die. This bevel obviates having the dies in extremely accurate axial alignment.

From the above description. it will be seen that I have provided a very eflicient method and apparatus for forming a grooved or'threaded cap or ring. The grooves or threads are perfectly fomed in the cap and the cap can very readily be removed from the die assembly (5. In practice the caps will be removed by operators stationed about the turret Hi. It Wil be noted that there are openings or passages 28a and 24a through the screws28. and 24 respectivelyand passagesliia in themembers 23. Any air that might be trapped in the dies can thus readily escape. It will be noted that the cap is held on the inner die. andis surrounded by the outer die before any compression of the same takes place. This obviates moving an inner die into an outer die with the cap compressed in such movement. In the present apparatus the'compression is done by the portions I60, I and-18o after the caphas been surrounded. A metal die thus does not have to enter another metal member in which it closely fits. taining an extremely accurate axial alignment of the upper and lower die asemblies. With the apparatus shown, the caps can be made at a very rapid rate. As described, they are successively acted on by the upper die assemblies l6, l1 and I8 to be formed as desired and are then removed as the lower dies move away from the plunger head 21. The method and apparatus have been amply demonstrated in actual practime and found to be very successful and efficient.

It will of course, be understood that various changes may be made in the form, details, arrangement and proportions of the apparatus and in the steps andsequence of steps of the method without departing from the scope of applicants invention, which generally stated, consists in a method and apparatus capable of carrying out the objects above set forth, such as disclosed and defined in the appended claims.

What is claimed is:

1. The method of forming a thread on acap having a cylindrical flange thereon which consists in forming circumferentially spaced grooves on said flange at circumferentially spaced portions thereof in one pressing operation by com This also eliminates the necessity of mainpressing said-'flange longitudinally to force it 2. An apparatus. for forming a grooved cap orring: having in combination, an inner die having a. continuous periphery withav peripheral rib formed thereon, a, rigid outer die adapted to move. over a cap-placedon said inner die and.

compress the same: longitudinally, said outer die having" 'circumierentially spaced portions for tightly'engaging saidcap. when the same is compressed longitudinally and -circum=ierentially spaced portions of largerv transverse dimension remaining free. of said cap when the latter is compressed longitudinally, a second rigid outer die adapted to move over said inner die in a subsequent operation and compress said cap longitudinally and having circumferentially spaced portions for tightly engaging said cap when compressed. in said subsequent operation and circumferentially spaced portions of larger transversedimension remaining free of said cap when the same is compressed in said subsequent operation, said. latter portions being arranged circumferentially so as to be disposed between the 'corrmponding portions on said first mentioned outer die whereby in successive operations different portions of said cap will be pressed against said inner die to form a substantially complete groove therein.

An apparatus/for forming a grooved cap having in combination, an inner die having a continuous substantially cylindrical portion with a circumferentially extending projecting rib thereon, a rigid outer die-havinga substantially cylindrical portion, adapted to move over'said inner die and a cap carried thereon, means for compressing said cap longitudinally, saidputer die having circumferentially spaced portions of onedimension tightlyfltting saidvcap against which and. said rib said cap is-ror'ced by said means andcircumferentially. spaced portions be. tween. said portions or a larger transverse 'dimension remaining free. of said cap when the same is compressed, a second outer die adapted to move over said cap and inner die in a subsequent operation, said latter die having circumferentially spaced portions of one dimension against which and said rib said cap is forced by said means and circumferentially spaced portions of a larger transverse dimension remaining free of said cap when the sameis compressed. said outer dies being arranged relatively to said inner die so that said portions of larger dimension are alternately disposed.

4. An apparatus for forming a cap with a grooved or threaded inner wall having in combination. inner and outer dies having threadforming means on one of the same, means for compressing said cap longitudinally between said dies, said first mentioned means having circumiferentially spaced operative portions and inoperative portions between said portions.

5. An apparatus for forming a threadpn the flange of a cap having in combination, an inner die adapted to receive said cap and having a continuous periphery about which said flange extends, a rigid outer die adapted to surround said cap and die, means for compressing said flange longitudinallybetween said dies, said dies having cooperating portions against which said flange is pressed by said compression to form a thread thereon; said portionsbihg interrupted.

at circumferentially spaced parts of one of said dies.

6. An apparatus for forming a thread on the cylindrical flange of a cap'having in'combination, an inner die having a continuous periphery adapted to be disposed in said flange, a rigid outer die adapted to surround said flange and die, said dies having cooperating portions adapted to press the wall of said flange therebetween to form a groove therein, said portions on said outer die being circumferentially spaced, and a second outer die having similar circumferentially spaced portions adapted to alternate with said spaced portions in said first mentioned outer die in cooperation with said inner die whereby a completed groove is formed in said flange and means for longitudinally compressing said flange between said dies in successive steps to force said flange thereagainst in successive steps.

7. An apparatus for forming a threaded cap having in combination, an inner die having a continuous periphery with a projecting rib thereon, an outer die having a continuous'inner wall adapted to surround said inner die and flange, means for compressing said flange longitudinally between said periphery and wall to force the same thereagainst to form a rib and groove therein, said outer die having circumferentially spaced portions of a size to closely engage said cap and having circumferentially spaced portions of larger transverse dimension remaining free of said cap.

8. An apparatus for forming a thread on the cylindrical flange of a cap having in combination, a rigidly mounted lower die having a surface to support the edge of said flange and having a continuous yielding portion with a peripheral wall disposed at the inner side of said flange, a rigid outer die adapted to move over said flange on said periphery of said lower die, said dies comprising thread-forming means, said outer die being mounted for resilient. movement, said outer die having a rigidly mounted upper portion adapted to engage the top of said cap to compress said flange longitudinally and force it against said thread-forming means.

8 9. The structure set forth in claim 8, said last mentioned portion of said upper'die havinga V-shaped ring on its lower surface for-forming a.

circumferentially extending groove in the top of said cap adjacent the edge thereof, and having a rib adjacent its top for forming a bevel at theouter edge of said cap on the top thereof.

10. An apparatus for forming a thread on the substantially cylindrical flange of a cap having in combination, inner and outer rigid 'dies' adapted to receive said flange thereb'etween and surround the same, said dies including circumferentially spaced meansfor pressing partner a thread in said flange, said means being operated in successive steps with said dies in difierent circumferential relation. whereby said flange can be easily removed from said dies and a complete thread is formed therein and means for compressing said flange longitudinally in said successive steps to press it against said dies.

11. The method of forming a thread on the substantially cylindrical flange of a cap which consists in disposing said flange between rigid inner and outer dies, said dies including circumferentially spaced means for pressing part of a thread in said flange, compressing said flange longitudinally to force it against said dies in successive steps with said dies in difierent circumferential relaton whereby a complete thread is formed in said flange.

LAWRENCE G. ZESBAUGH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

